King Fahd University of Petroleum and Minerals is a public university in Dhahran, Saudi Arabia. Among Saudi universities, its science and engineering programs are highly regarded. It offers some programs that are not offered elsewhere in Saudi Arabia. Wikipedia.
Aldawoud A.,King Fahd University of Petroleum and Minerals
Energy and Buildings | Year: 2013
Electrochromic glazing or exterior shading devices offer shading of the intense direct sun, reduce glare, and improve the daylight luminance within buildings. Additionally, they are important factors affecting energy performance of buildings as they impact the heating and cooling consumption. This analysis investigated the performance and the effectiveness of electrochromic glazing to prevent unwanted solar heat gains from entering a conditioned space. Then, these performances are compared to those offered by conventional fixed exterior shading devices in identical conditions. The aim of this analysis is to provide architects and designers with general guidance and appropriate design strategies for different window treatments and shading techniques during early design stages in hot, dry climate. A typical office building is modeled using DesignBuilder software. Building envelope characteristics, internal loads, and operating schedules including schedules for equipment, occupancy, interior lighting, heating, ventilating, air conditioning, and weather data are all unchanged throughout the simulation process. The windows shading condition and the glazing type are the only varying parameters. The output data show that electrochromic glazing provides the best performance in reducing solar heat gains compared to other tested shading conditions. © 2013 Elsevier B.V.
Mahmoud M.S.,King Fahd University of Petroleum and Minerals
Automatica | Year: 2012
In this paper, we study the problem of designing decentralized reliable state-feedback controllers under a class of actuator failures for a class of linear interconnected discrete-time systems having subsystem and coupling time delays. The failures take into consideration possible outages or partial failures in every single actuator. A decentralized stabilizing reliable feedback controller is derived at the subsystem level to give the closed-loop subsystem delay-dependent robust internal stability with a γ-level ℓ 2-gain. The results developed are tested on a representative water quality control example. © 2012 Elsevier Ltd. All rights reserved.
Saleh T.A.,King Fahd University of Petroleum and Minerals
Applied Surface Science | Year: 2011
The nature of multi-walled carbon nanotubes (MWCNTs) varies with the change in oxidation conditions. In this work, the effect of treatment temperatures on the acidity of MWCNTs was studied. Oxidation was performed by refluxing the MWCNTs in nitric acid or mixtures of sulfuric acid and nitric acid at different temperatures. After oxidative treatment, a quantitative characterization of o-MWCNTs has been performed using acid-base titrations which show that the number of surface acidic functional groups increased by increasing the treatment temperatures. Energy dispersive X-ray (EDX) measurements show that the oxygen content increased with increasing treatment temperatures. Fourier transform infrared absorption spectroscopy (FTIR) was used for qualitative characterization. It has been demonstrated that the acidity is a function of the type of oxidizing agent used and the treatment temperatures. Due to the importance in attachment strategies and functionalization, this study adds to the global discussion of the possibility of controlling the MWCNTs' surface chemistry which plays a crucial role in determining its reactivity. © 2011 Elsevier B.V. All rights reserved.
Al-Sulaiman F.A.,King Fahd University of Petroleum and Minerals
Energy Conversion and Management | Year: 2014
In this paper, detailed exergy analysis of selected thermal power systems driven by parabolic trough solar collectors (PTSCs) is presented. The power is produced using either a steam Rankine cycle (SRC) or a combined cycle, in which the SRC is the topping cycle and an organic Rankine cycle (ORC) is the bottoming cycle. Seven refrigerants for the ORC were examined: R134a, R152a, R290, R407c, R600, R600a, and ammonia. Key exergetic parameters were examined: exergetic efficiency, exergy destruction rate, fuel depletion ratio, irreversibility ratio, and improvement potential. For all the cases considered it was revealed that as the solar irradiation increases, the exergetic efficiency increases. Among the combined cycles examined, the R134a combined cycle demonstrates the best exergetic performance with a maximum exergetic efficiency of 26% followed by the R152a combined cycle with an exergetic efficiency of 25%. Alternatively, the R600a combined cycle has the lowest exergetic efficiency, 20-21%. This study reveals that the main source of exergy destruction is the solar collector where more than 50% of inlet exergy is destructed, or in other words more than 70% of the total destructed exergy. In addition, more than 13% of the inlet exergy is destructed in the evaporator which is equivalent to around 19% of the destructed exergy. Finally, this study reveals that there is an exergetic improvement potential of 75% in the systems considered. © 2013 Elsevier Ltd. All rights reserved.
Al-Hadhrami L.M.,King Fahd University of Petroleum and Minerals
Renewable and Sustainable Energy Reviews | Year: 2013
This paper presents the annual and seasonal cooling (CDD) and heating (HDD) degree day values over Saudi Arabia by utilizing the long-term daily average temperatures from 38 meteorological stations. The values of CDDs and HDDs have been calculated for a base temperature of 18.3 C. The maximum annual mean CDDs of 7549 were observed at Makkah while the minimum of 3132 at Abha. On the other hand the maximum HDDs of 985 were found in Guriat and minimum of 0 at Gizan, Jeddah, Rabigh, Makkah, Sabya, Sharourah, Wejh and Yanbu. The annual and seasonal values of CDD and HDD provided in this paper could be used to estimate the fuel or energy requirement for cooling or heating of buildings in respective areas both on annual and seasonal bases. © 2013 Published by Elsevier Ltd.